Storage battery and gravity indicating means



E. F. H. eRo l-l 2,061,573

' Filed Jan 18, 1933 9 w w u J I l I I I I l I I 1 I I I I I 1 l [I I Nov. 24, 1936.

' STORAGE BATTERY AND GRAVITY INDIGATING MEANS Patent ed ,Nov. 24, 1936 UNITED STATES PATENT OFFICE hare Ernest F. H. Grothe, Philadelphia, Pa... assignor to The Electric Storage Battery Company, Philadelphia, Psi, a corporation of New Jersey Application January 18, 1933, Serial No. 652,298

1 Claim.

' The subject of my invention is an electric storage battery cell having a hydrometer syringe containing means for indicating the specific gravity of the electrolyte of the storage battery therein. The hydrometer syringe is removably mounted in the vent plug of the storage battery.

One feature of my invention is that the barrel of the syringe fits loosely in the opening through the vent plug and the barrel itself has a shoulder or. collar formed integrally with the-material of the barrel which shoulder supports the syringe onthe vent plug.

Another feature is that there is a vent opening through the vent plug at one side of the openl5 ingwhich contains the barrel of the hydrometer syringe. For a further exposition of my invention reference may be had to' the annexed specification and drawing at the end whereof my invention will be specifically pointed out and claimed.

The single figure of the drawing is a view in side elevation with parts' in vertical cross section and with parts brolcen away.

In the drawing there is shown a storage battery'having a'casing generally indicated at I and adapted to contain the customary electrolyte indicated at 2. The casing I supports a cover 3 which is connected to the casing I so that no gas escapes therebetween. Casing l and cover 3 together form a container for the storage battery and its electrolyte 2. i

Cover 3 carries a vent plug 4 thereon. .Vent plug 4 has a large hole 5 extending therethrough and cooperating with a hole 6 in cover}. Adjacent hole 5 in vent plug 4 is a vent opening I which communicates below with the interior of the cell through the hole 6.

Throughholes 5 and 6 extends the barrel 9 which forms part of a hydrometer syringe. Barrel. 9 is preferably made of glassor other transparent, acid resistant material. ,Barrel 9' has on its outer surface acollar l0 formed integral with the material of the barrel andot 45 somewhat larger diameter than hole 5.

Within barrel 9 there is located-means II for indicating the specific gravity of the electrolyte 2 of the storage battery when the ,same is' drawn into the barrel 9 through the opening J2 in the bottom of the barrel.

At its upper end barrel 9 carries a bulb 13 conveniently made of rubber or other flexible, acid resistantv material. Bulb l3 carries a boss l4 thereon. In the center of boss ll there is located u a permanently open hole l5.

It is to be noted that barrel 9 fits loosely in holes 5 andi and is supported on vent plug 4 by the engagement of collar or shoulder ill with the top of the vent plug.

Vent opening 1 permits th'euescape of gas from 5 the cell'when the syringe isin the position shown. Vent opening 'I prevents the spitting of electro- 'lyte which would otherwise occur at the top of the space between collar III on barrel 8 and vent plug 4. .This space being comparatively small 10 acts by capillary action to retain a film of electrolyte which is sprayed from the surface of the electrolyte in the cell'during the gassing period and accumulates on the under surface of the cover 3 and ventplug 4, and on the surface of 15 barrel 9. It 1 is found that the separate vent opening 1 prevents this spitting. c When it is desired to draw electrolyte 2 intc barrel-iL'bulb i3 is pressed, as may conveniently be doneby hand,with'opening l5 open to permit 0 the escape of air or other gas fromwithin the bulb I3. Opening I5. is then closed, as by covering it with the hand, and the bulb I3 permitted to expand thus drawing electrolyte v2 from the casing I' through the opening I: into the barrel 9 and floating the indicating means II in the electrolyte. When the opening i5 is again uncovered the electrolyte in barrel 9 drains back into the cell.

If desired, vent plug 4 and cover 3 can be com- 30 bined into one integral structure.

I do not intend to be limited to the practice 0! my invention save as the scope of the prior art and of the attached claim may require.

An indicatingdevice including, in combination, a storage battery containing electrolyte, a vent plug having a hole therethrough mounted on said storage battery, 9. hydrometer syringe having a glass barrel loosely fitting in said hole so 40 that said syringe is detachably mounted in said vent plug, a shoulder formed of the glass of said barrel intermediatethe ends thereof and supporting said syringe in said vent plug so that the major portion of said barrel is outside the battery and is visible, said vent plug having a vent opening therethrough located between said barrel and the wallet said hole and underlying said shoulder so that 'said, vent opening is open when said nauss'r sin. GROTHE. 

